The present invention relates to a digitizer board, and more particularly, to a digitizer board which is made of magneto-resistors (MR).
A digitizer is a graphics input peripheral device for a computer system. The digitizer generally comprises a plurality of sensing members arranged in an array on a board. The sensing members are capable of sensing a physical quantity and sending a digital signal indicating the position where the physical quantity is sensed to the computer system.
A number of elements have been utilized as the sensing member for prior art digitizers. These elements include magnetoresistive, electromagnetic inductive, electrostatic, piezoelectric, and photoelectric element, etc.
A magneto-resistor is an element whose resistance is changed when a magnetic field is applied thereto. Referring to FIG. 1, there is shown a characteristic curve of resistance against magnetic flux density for a magneto-resistor. As can be seen, the curve is substantially linear when the applied magnetic flux is larger than about 2600 Gauss. The larger the magnetic flux density acting on the magneto-resistor, the larger the resistance of the magneto-resistor becomes. Therefore, the magneto-resistor can be utilized for sensing a physical quantity of magnetic flux densities.
Conventional applications of magneto-resistors include the use of it as a rotational speed detector or as a displacement detector etc.